title: Strigolactones regulate protonema branching and act as a quorum sensing-like signal in the moss Physcomitrella patens.
abstract: Strigolactones are a novel class of plant hormones controlling shoot branching in seed plants. They also signal host root proximity during symbiotic and parasitic interactions. To gain a better understanding of the origin of strigolactone functions, we characterised a moss mutant strongly affected in strigolactone biosynthesis following deletion of the CAROTENOID CLEAVAGE DIOXYGENASE 8 (CCD8) gene. Here, we show that wild-type Physcomitrella patens produces and releases strigolactones into the medium where they control branching of protonemal filaments and colony extension. We further show that Ppccd8 mutant colonies fail to sense the proximity of neighbouring colonies, which in wild-type plants causes the arrest of colony extension. The mutant phenotype is rescued when grown in the proximity of wild-type colonies, by exogenous supply of synthetic strigolactones or by ectopic expression of seed plant CCD8. Thus, our data demonstrate for the first time that Bryophytes (P. patens) produce strigolactones that act as signalling factors controlling developmental and potentially ecophysiological processes. We propose that in P. patens, strigolactones are reminiscent of quorum-sensing molecules used by bacteria to communicate with one another.
authors.affiliation: Institut Jean-Pierre Bourgin, UMR 1318 INRA-AgroParisTech, Centre de Versailles-Grignon, Versailles Cedex, France.
authors.forename: Hélène
authors.initials: H
authors.lastname: Proust
authors.forename: Beate
authors.initials: B
authors.lastname: Hoffmann
authors.forename: Xiaonan
authors.initials: X
authors.lastname: Xie
authors.forename: Kaori
authors.initials: K
authors.lastname: Yoneyama
authors.forename: Didier G
authors.initials: DG
authors.lastname: Schaefer
authors.forename: Koichi
authors.initials: K
authors.lastname: Yoneyama
authors.forename: Fabien
authors.initials: F
authors.lastname: Nogué
authors.forename: Catherine
authors.initials: C
authors.lastname: Rameau
mesh_terms: D019068:Bryopsida / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D049308:Dioxygenases / Q000235:genetics / Q000378:metabolism; D007783:Lactones / Q000378:metabolism*; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D053038:Quorum Sensing / Q000502:physiology; D015398:Signal Transduction
chemical_list: D007783:Lactones; D010940:Plant Proteins; D049308:Dioxygenases